1. Field of the Invention
The invention relates to a multiple fuel tank system for an automotive vehicle. In one of its aspects, the invention relates to the fuel filling conduit system for a dual fuel tank system. In another of its aspects, the invention relates to a fuel filling and vapor venting system for a dual fuel tank system in a vehicle. In another of its aspects, the invention relates to a tubing connector configured to direct all fuel entering an inlet port to a first outlet port, and responsive to conditions at the first outlet port to redirect flow to a second outlet port.
2. Related Art
Multiple fuel tank systems for automotive vehicles are well known, for increasing fuel capacity in an automotive vehicle to increase its driving range. Numerous methods have been employed to provide a filling capability for the multiple fuel tanks as well as the capability for drawing fuel from those tanks to feed the internal combustion engine of the vehicle. Structures for filling the fuel tanks have ranged from having individual fuel inlet ports, for instance on each side of the vehicle, to a single fuel inlet port with a Y-type connector to split the fuel flow. Another system, disclosed in U.S. Pat. 5,983,932 and commonly owned, comprises a cross-flow pipe between the multiple fuel tanks to allow simultaneous filling of the fuel tanks from a single inlet port. As the fuel level in a first fuel tank rises, the fuel will naturally flow to the second fuel tank, the fuel seeking its own level between the connected tanks.
An alternative method of filling multiple fuel tanks is disclosed in U.S. Pat. No. 4,765,359, which discloses multiple fuel inlet ports, preferably located on opposite sides of an automotive vehicle, connected to a common fuel tank filling manifold, whereby pumping fuel into either of the inlet ports directs fuel into the manifold, thereby filling the fuel tanks.
A common limitation of the prior art fuel tank systems is that effective filling of the multiple fuel tanks is largely dependent upon relative fill levels between tanks, fuel and ambient temperature, fuel reid vapor pressure, and vehicle attitude.
For instance, if the vehicle is sitting on an incline, a fuel tank on the lower end of the incline will be filled sooner than higher fuel tanks, thus potentially shutting off the fuel flow prior to complete filling of the tanks, or causing an overflow through any vapor exhaust systems prior to completely filling both of the tanks. Another issue in dealing with multiple fuel tanks occurs in the cross-feed conduits. Located near the bottom of the fuel tanks to maintain a common level in the tanks, they can often be plugged by contaminants that settle to the bottom of the tanks, or can be blocked by water that settles to the bottom of the tanks and then freezes in the cross-feed conduit. In such a condition, fuel drawn from one of the tanks to feed the internal combustion engine could not be appropriately replenished by the second fuel tank, or filling the tanks from a single fuel inlet port would fill the first tank, but not the second tank now fluidly isolated due to the plugged conduit.
It would be advantageous to provided a dual tank simultaneous fill system that is not susceptible to the limitations of a cross-feed conduit, and is a further adaptable to filling both tanks to capacity independent of the attitude of the vehicle during fueling.
The invention relates to a fuel supply system for an automotive vehicle of the type having an internal combustion engine, the fuel supply system including at least two fuel storage tanks, a fuel pumping mechanism for transporting fuel from at least one of the storage tanks to the engine, a fuel transfer system for conveying fuel from one of the storage tanks to another of the storage tanks, and a fuel filling system for adding fuel to the system from a gas station, the fuel filling system comprising a single fuel inlet port. The fuel supply system further includes a T-connector fluidly connecting the fuel inlet port with the at least two fuel storage tanks, the T-connector including an inlet opening and first and second outlet openings, the first outlet opening fluidly connected to a first tank and the second outlet opening fluidly connected to at least a second storage tank, the T-connector configured to direct all fuel through the first outlet opening until the first tank is full, then to direct fuel through the second outlet opening.
Other objects, features, and advantages of the invention will be apparent from the ensuing description in conjunction with the accompanying drawings.